This proposal is to request support for a Keystone Symposia meeting entitled "RNAi, MicroRNA, and Non-Coding RNA", organized by Judy Lieberman and Phillip A. Sharp, which will be held in British Columbia, Canada from March 25 - 30, 2008. RNA interference (RNAi) describes a variety of evolutionarily conserved mechanisms for regulating gene transcription and post-transcriptional events that are important for controlling development and cell proliferation, survival, differentiation and effector functions. RNAi also protects the genome from transposons and viruses. This meeting will explore recent developments in understanding the molecular mechanisms and cell biology of RNA-based post-transcriptional silencing and for maintaining regions of silenced chromatin. It will consider methods to uncover regulatory networks of endogenous microRNAs and their target genes and illustrative examples in a variety of organisms. Recent advances in harnessing RNA interference for genetic screening and therapeutic gene silencing will also be explored. [unreadable] [unreadable] [unreadable] [unreadable]